A top model has accused the husband of a rival fashion model of sexually assaulting her during London Fashion Week.

New York hair stylist Shawn Mount, 30 — who is married to Karl Lagerfeld muse and face of Chanel Heidi Mount — was questioned by British police over the alleged attack on another 24-year-old model, whom we have agreed not to name, in a central London hotel room in the early hours of Sept. 20.

Shawn, who has styled for Vogue and ad campaigns for Ralph Lauren, was in London primping models for the runway shows. He was arrested and released on police bail to work at Milan’s fashion week.

A Scotland Yard spokesman told us: “We received a complaint of a serious sexual assault at 1:30 a.m. on Sept. 20 at a central London hotel. The 24-year-old victim was referred to the Haven Centre [which helps alleged victims of sexual assaults.] A 30-year-old man was arrested on Sept. 21 on suspicion of rape and bailed to return to a London police station in November. He has not been charged and we are still investigating.”

The details of the woman’s allegations have not been released by police, but sources tell us both Mount and his wife, who was in Milan at the time of the alleged attack, know the alleged victim.

A source told us: “This is devastating for both women. Shawn denies the allegation.”

A rep for the alleged victim declined to comment. Mount did not respond to e-mails or calls. A spokeswoman at his agency, Artlist New York, declined to comment.

Heidi — who replaced Claudia Schiffer as the face of Chanel in 2009, models for Dolce & Gabbana and has walked in runway shows for Michael Kors, Dior, Givenchy and Valentino — married Shawn in 2007. They have a 3-year-old son and live in the East Village. Her rep also declined to comment.